Rainfall Trends and Extremes in Saudi Arabia in Recent Decades

Mansour Almazroui

doi:10.3390/atmos11090964

Abstract

The observed records of recent decades show increased economic damage associated with flash flooding in different regions of Saudi Arabia. An increase in extreme rainfall events may cause severe repercussions for the socio-economic sectors of the country. The present study investigated the observed rainfall trends and associated extremes over Saudi Arabia for the 42-year period of 1978–2019. It measured the contribution of extreme events to the total rainfall and calculated the changes to mean and extreme rainfall events over five different climate regions of Saudi Arabia. Rainfall indices were constructed by estimating the extreme characteristics associated with daily rainfall frequency and intensity. The analysis reveals that the annual rainfall is decreasing (5.89 mm decade−1, significant at the 90% level) over Saudi Arabia for the entire analysis period, while it increased in the most recent decade. On a monthly scale, the most significant increase (5.44 mm decade−1) is observed in November and the largest decrease (1.20 mm decade−1) in January. The frequency of intense rainfall events is increasing for the majority of stations over Saudi Arabia, while the frequency of weak events is decreasing. More extreme rainfall events are occurring in the northwest, east, and southwest regions of Saudi Arabia. A daily rainfall of ≥ 26 mm is identified as the threshold for an extreme event. It is found that the contribution of extreme events to the total rainfall amount varies from region to region and season to season. The most considerable contribution (up to 56%) is found in the southern region in June. Regionally, significant contribution comes from the coastal region, where extreme events contribute, on average, 47% of the total rainfall each month from October to February, with the largest (53%) in November. For the entire country, extreme rainfall contributes most (52%) in November and least (20%) in July, while contributions from different stations are in the 8–50% range of the total rainfall.

Highlights

Extreme rainfall events have severe socio-economic impacts, often resulting in droughts, strong winds, and flash floods, and disrupting the environment, including the human population [1,2].any changes in the frequency and intensity of such events are of significant interest.The Intergovernmental Panel on Climate Change (IPCC) has resolved with a high confidence level that the frequency of extreme rainfall events will increase under the influence of global warming in some parts of the world [3]
The inter-annual variability of rainfall largely modulates the extreme events in semi-arid to arid regions such as Saudi Arabia, where such events make up a significant fraction of the total annual rainfall
The heterogeneous spatial distribution of rainfall from north to south over Saudi Arabia is shown by the CHIRPS and Global Precipitation Climatology Centre (GPCC) data (Figure 2)

Summary

Introduction

Extreme rainfall events have severe socio-economic impacts, often resulting in droughts, strong winds, and flash floods, and disrupting the environment, including the human population [1,2].any changes in the frequency and intensity of such events are of significant interest.The Intergovernmental Panel on Climate Change (IPCC) has resolved with a high confidence level that the frequency of extreme rainfall events will increase under the influence of global warming in some parts of the world [3]. Extreme rainfall events have severe socio-economic impacts, often resulting in droughts, strong winds, and flash floods, and disrupting the environment, including the human population [1,2]. Any changes in the frequency and intensity of such events are of significant interest. The Intergovernmental Panel on Climate Change (IPCC) has resolved with a high confidence level that the frequency of extreme rainfall events will increase under the influence of global warming in some parts of the world [3]. Climate change often appears as an increase in the intensity and frequency of extreme weather events. It is essential for us to complete historical trend assessments, including for extreme events [5]. The spatial distributions of inter-annual rainfall over the country stem from climate variability, which is further associated with droughts and disastrous

Methods

Results

Conclusion